Answer:
Length: 18
Width: 11
Explanation:
Step 1: Write out equation
x(x + 7) = 198
Step 2: Distribute
x² + 7x = 198
Step 3: Complete the square
x² + 7x + 49/4 198 + 49/4
(x + 7/2)² = 841/4
Step 3: Solve for x
√(x + 7/2)² = √(841/4)
x + 7/2 = ±29/2
x = -7/2 ± 29/2
x = 11, -18
Since you can't have negative length, your x will be 11. Now simply plug them in as width and length:
Width = x
x = 11 in
Length = 11 + 7
x = 18 in
And we have our final answers!